Antirattling gear



May 25,*193'1'.'vv EHSMYTHE 2,081,644

ANTIRATTLING GEAR y Filed Sept. 26, 1936 "gramm www llwil mmm plummmwmmINVENTOR.

ATTORNEY.

lBY

Patented AMay 25, 1937 UNITED STA'ES PATENT GFFICE ANTIRATTLING GEAREthelbert Hamilton Smythe, Detroit, Mich.

Application September 26, 1936, Serial No. 102,673

6 Claims.

This invention relates to anti-rattling gears, the purpose being toprovide a gear for use in various types or" installations as, forinstance, transmission gearing of an automobile, so constructed that noback lash will occur between the teeth of the gear and the companiongear engaging therewith.

The teeth of the usual gears and pinions are constructed to provide forclearance which increases due to wear in use resulting in an increasingand undesirable noise in operation.

The object of this invention is to provide a two-part gear for meshingwith a pinion, both of which gear parts are formed with complemen- V talteeth that may register and the combined end to end length of which isapproximately the same as the teeth of the pinion meshing therewith inassociation with which I provide a hydraulic means for causing arelative rotation of one part of the two-part gear to the other and thusthe two-part teeth of the gear, in engaging between the teeth of thepinion, respectively engage the side faces of the adjacent teeth of thepinion.

A further feature and object of the invention is to provide a two-partgear for use in conjunction with an internal combustion engine in whichthe wearing parts are supplied with oil under pressure as by means of apump, a part of the conduits supplied with oil under pressure leadingthrough one of the gear parts and discharging to between the parts torecesses having abutments against which the oil applies pressure tocause relative rotation of the other gear part to offset the teeth.

These and other objects and novel features of the invention arehereinafter more fully described and claimed, and the preferred form ofconstruction of a gear embodying my invention is shown the accompanyingdrawing in which- Fig. l is an end elevation of the two-part gear andportion of a pinion meshing therewith.

Fig. 2 is a section taken on line 2 2 of Fig. l showing the oil channelsin one part of the gear and recesses in the other whereby oil underpressure tends to rotate the recessed gear part relative to the otherpart.

Fig. 3 is a section taken on line 3 3 of Fig. l.

The gear embodying my invention is formed of two parts I and 3, the partI having a hub secured to the shaft 2 by which it is driven and theother part 3 of the gear is rotatably mounted on and in face contactwith the relatively fixed gear part I. The hub 4 of the gear part I ispreferably provided with at least three arcuate portions 5 spacedcircumierentially about the hub and these portions 5 are undercut toprovide a groove to receive corresponding tongues 6 of the gear 3. Thegear part 3 may be mounted in the desired relationship with the gearpart I by :Introducing the portions 6 of the gear part 3 between theportions 5 of the gear part I whereupon the gear part 3 is rotated sothat the tongues is lie beneath the projections 5 of the gear part I andsustain the same in position. Both these gear parts have complementalteeth l and l and these are brought to alignment and together meshbetween the teeth 8 of the pinion 9.

The shaft 2 on which the gears are mounted is formed with an oilpassageway I supplied with oil under pressure in any approved manner.There is a ball check valve I2 in the passageway IIJ at the end of theshaft supported by a spring I3 under such tension that oil may notdischarge through the shaft except at certain pressure. The shaft has acircumferential groove I4 which is open at at least one point to thepassageway IB in the shaft 2 by the radial passageway i5. The-re is anapertured plug I8 at the end of the shaft which supports the check valveopening and tension of the spring limits the oil pressure. The gear Ihas at least two radial passageways II and Iii registering at one endwith the groove I4 and extending to near the periphery of the gear andterminating in a transverse passageway I9 and 2li' for the respectivepassageways il and I8. The transverse passageways open through the innerface of the -gear I as will be clearly understood from Figs. 2 and 3.The inner and contacting face of the gear 3 has recesses 2i formed withan inclined side wall 22 and a wall 23 at a right angle to the innerface of the gear and the channels I9 and 2li open to these respectiverecesses. Oil feeding under pressure thro-ugh the several passageways tothe recesses 2l tends to rotate the gear part 3 relative to the gearpart I and thus offset the teeth 'I and 'I' to the extent permitted bythe space between the teeth of the driving pinion 9. The arrangementthus provides for limited pressure contact of the teeth of the two partsof the driven gear with the teeth of the pinion and prevents back lashor noise in the operation of the gear.

For general purposes, the oil may be supplied under pressure in anyconvenient way (not here shown). In use of the gear in parts of atransmission mechanism, timing gear, or other gear parts associated withan internal combustion engine of an automobile, the passageway IB is tobe understood as being connected with a branch of the oil supplyingconduits commonly provided in such character of engine construction,which conduits in general lead to various bearings to with certaintymaintain the bearings oiled. The conduit ill being connected with suchsupply source will be free from oil under pressure when the engine isnot in operation. Upon initially starting the engine, oil will beindirectly transmitted to the gear parts when sufficient pressure hasbeen developed in the oil conduit It to unseat the ball check valve l 2.Oil not only flows through the apertured plug I6 but also ows throughthe passageway Iii, Il, I8, I9 and 20 to the recesses 2i of the gearpart 3 tending to rotate the same slightly relative to the gear part Ias may be permitted by the space between the teeth of the pinion withwhich it meshes. By providing for a release of oil pressure, thepressure between the teeth of the two-part gear and the pinion issuiicient to prevent back lash but insuilcient to cause a grindingnoise, or growl as it is sometimes termed, commonly occurring in gearshaving xed teeth.

There is but slight movement of the -gear part I 3 under influence ofhydraulic pressure due to the limitation of movement by the spacebetween the pinion teeth and thus the inwardly extending lug portions iof the gear 3 do not in operation move suiciently to pass from beneaththe outwardly projecting portions 3 extending thereover but theseportions 5 of the gear i are so relatively spaced that the portion 6can, in the assembly of the gear parts, be positioned rstly between theportions 5 of the gear part l and then rotated to bring the portion tbeneath the portions 5 and thus align the recesses 2l with thetransverse passageways i 9 and 2Q of the gear p-art l and the gear partsi and 3 are retained in this operative relationship by the teeth of thepinion 9 meshing therewith.

From the foregoing description, it will be evident that the structuredescribed is of such character as to secure the various objects of theinvention and that the device is comparativey simpleand inexpensive andnaturally effective in operation.

Having thus briey described my invention, its utility and mode ofoperation, what I claim and desire tol secure by Letters Patent of theUnited States is- 1. An anti-rattling gear comprising a two-part toothedgear having the parts thereof in face to face relationship, one of saidparts being revoluble relative to the other to offset the teeth for thepurpose stated, and hydraulic means for causing rotation of therotatable part relative to the other.

2. An anti-rattling gear comprising atwo-part gear having the partsthereof in a face to face relationship, said parts having complementalteeth and one of the said parts being revolubly mounted on the other tooffset the respective teeth for the purpose stated, and hydraulicl meansfor causing rotation of one said part relative to the other.

3. An anti-rattling gear comprising a gear having two parts in a face toface relationship, the two parts having complemental teeth and one ofthe said parts being revoluble relative to the other, said other parthaving passageways opening through the face thereof contacting the faceof the revoluble part, the rst part having recesses opening through theface thereof and formed with an abutment at a right angle to thecontacting faces of the two gear parts, and means for providing iiuidunder pressure to the said passagewaysrto engage the said abutments andcause the rotatable gear to turn in respect to the other gear part tooiset the teeth thereof whereby, in association with another toothedgear, the oiset teeth respectively engage opposite side faces of theteeth of the gear between which they engage.

4. An anti-rattling gear comprising a gear formed of two similar partsprovided with complemental teeth and lying in face to face relationship,one of the said gear parts having a hub for attachment to a shaft andprovided with extending lugs in spaced relation to the adjacent sideface of the gear part, the other of said gear parts being relativelyrevoluble and having a central aperture provided with similar inwardlyextending lugs for engagement in the space between the lugs or" the saidhub and adjacent face of the first gear part whereby the gear parts areheld in a close face to face relationship, the said shaft having apassageway and the hubbed gear having radial passageways opening theretoat one end and extending to near the periphery and opening at the otherend through the face thereof in Contact with the rotatable gear, saidrevoluble gear part having recesses registering with the said opening ofthe passageways through the face of the other gear part when the lugs ofthe revoluble gear are in position between the lugs of the hub, the saidrecesses being formed with a surface inclined to the contacting faces ofthe gear and an abutment at a right angle thereto, and means forsupplying oil under pressure through the passageways to engage theabutments of the recesses and thereby turn the revoluble gear in respectto the iirst gear to thereby offset the teeth of the revoluble gearparts in respect to the iiXed gear part.

5. An anti-rattling gear for use in association with an internalcombustion engine driven gear set, including a pump and conduits for oilto the various engine parts, said gear including a shaft having apassageway communicating with the said oil conduits, said passagewayhaving an opening to atmosphere, a spring pressed valve normally closingthe passageway to atmosphere, whereby, when the engine is in operation,oil under pressure determined by the spring tension is delivered to thepassageway, the said two gear parts being in a face to face relationshipand L having complemental teeth, one of the gear parts being rotatablerelative to the other whereby the teeth of the one may be offset inrespect to the teeth of the other part, the one gear part having oilpassageways communicating with the said passageway of the shaft andopening through the face of said gear part in contact with the otherpart, said other part having recesses registering with the openings ofthe oil passageways of the other gear part providing a construction inwhich oil discharges under limited pressure to the passageways andrecesses of the respective gear parts and turns the rotatable gear partrelative to said other gear part.

6. An anti-rattling gear comprising a twopart gear, the two parts beingin face to face relationship and having complemental teeth, one of saidparts being revoluble relative to the other to offset the respectiveteeth for the purpose described, means responsive to hydraulic pressurefor causing rotation oi the rotatable gear part relative to the other,and means limiting the hydraulic pressure to which the gear parts may besubjected.

ETHELBERT HAMILTON SMYTHE.

